<?php
/**
 * CExistValidator class file.
 *
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @link http://www.yiiframework.com/
 * @copyright Copyright &copy; 2008-2011 Yii Software LLC
 * @license http://www.yiiframework.com/license/
 */

/**
 * CExistValidator validates that the attribute value exists in a table.
 *
 * This validator is often used to verify that a foreign key contains a value
 * that can be found in the foreign table.
 *
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @version $Id: CExistValidator.php 2799 2011-01-01 19:31:13Z qiang.xue $
 * @package system.validators
 * @since 1.0.4
 */
class CExistValidator extends CValidator
{
    /**
     * @var string the ActiveRecord class name that should be used to
     * look for the attribute value being validated. Defaults to null,
     * meaning using the ActiveRecord class of the attribute being validated.
     * You may use path alias to reference a class name here.
     * @see attributeName
     */
    public $className;
    /**
     * @var string the ActiveRecord class attribute name that should be
     * used to look for the attribute value being validated. Defaults to null,
     * meaning using the name of the attribute being validated.
     * @see className
     */
    public $attributeName;
    /**
     * @var array additional query criteria. This will be combined with the condition
     * that checks if the attribute value exists in the corresponding table column.
     * This array will be used to instantiate a {@link CDbCriteria} object.
     * @since 1.0.8
     */
    public $criteria=array();
    /**
     * @var boolean whether the attribute value can be null or empty. Defaults to true,
     * meaning that if the attribute is empty, it is considered valid.
     */
    public $allowEmpty=true;

    /**
     * Validates the attribute of the object.
     * If there is any error, the error message is added to the object.
     * @param CModel $object the object being validated
     * @param string $attribute the attribute being validated
     */
    protected function validateAttribute($object,$attribute)
    {
        $value=$object->$attribute;
        if($this->allowEmpty && $this->isEmpty($value))
        return;

        $className=$this->className===null?get_class($object):Yii::import($this->className);
        $attributeName=$this->attributeName===null?$attribute:$this->attributeName;
        $finder=CActiveRecord::model($className);
        $table=$finder->getTableSchema();
        if(($column=$table->getColumn($attributeName))===null)
        throw new CException(Yii::t('yii','Table "{table}" does not have a column named "{column}".',
        array('{column}'=>$attributeName,'{table}'=>$table->name)));

        $criteria=array('condition'=>$column->rawName.'=:vp','params'=>array(':vp'=>$value));
        if($this->criteria!==array())
        {
            $criteria=new CDbCriteria($criteria);
            $criteria->mergeWith($this->criteria);
        }

        if(!$finder->exists($criteria))
        {
            $message=$this->message!==null?$this->message:Yii::t('yii','{attribute} "{value}" is invalid.');
            $this->addError($object,$attribute,$message,array('{value}'=>$value));
        }
    }
}

